Please see Part 1 of this article for a discussion of what whey protein is, what it does, and the different types of whey protein. In this article, we’ll discuss dairy processing, other proteins and whey protein safety.
How does dairy processing affect the whey?
No one commercial process for concentrating whey from milk will leave the proteins entirely unaffected, compared to their presence within raw milk. That’s because most commercialized milk products undergo pasteurization and homogenization (at least to some extent).
Homogenization plus ultra-high temperature (UHT) processing have the most profound, and negative impact on the composition, loss and structure of the proteins present within whey, whereas high-temperature, short-time pasteurization (HTST) appears to maintain the proteins nearest to their native structure as they occur within raw milk.
As reported in the Journal of Dairy Science, maintenance of the proteins native within whey follow this order, from least to most adversely affected: Raw Milk > HTST = Homogenized = Homogenized + HTST > Skimmed + HTST = Skimmed + UHT > Homogenized + UHT.1
As a formulator, or when advising about the technical aspects of the whey used within your brand’s formulations, there are a few things to keep in mind. Despite claims to the contrary, “native” whey processing indeed requires the use of enzymes to separate the whey and casein. This “native” process takes place after the milk has been skimmed of fat and removes glycomacropeptides typically present in abundance within whey.
That isn’t to say that “native” whey is worse than rennet- or acid-derived whey, or vice-versa. Rennet enzymes can affect protein structures, and acid methods retain significantly higher concentrations of minerals, and can therefore be higher in heavy metals. Whether any of that matters is just marketing speculation, though. To date, no study has compared if there are any physiological differences in response to consuming whey protein derived from the same raw milk, but processed using different methods of commercialization. If someone would like to fund that study, my contact information is below.
How does whey compare to other proteins, such as casein or soy?
Whey has consistently been shown to outperform all other proteins when muscle protein synthesis (MPS) has been observed directly. The vast majority of the evidence supports the conclusion that whey is more effective than other proteins at supporting human performance outcomes, and improvements in body composition and immune function.2,3
For example, when 20 grams of whey or soy were consumed for 14 days, in combination with resistance training, soy resulted in a lower testosterone response to exercise; whereas, whey reduced the cortisol response to training.4 When just 10 grams of protein was consumed under fasting conditions, whey stimulated MPS by approximately 93 percent more than casein and 18 percent more than soy. Under the same conditions, but when the different proteins were consumed immediately after resistance training, whey was 122 percent and 31 percent more effective at stimulating MPS than casein or soy, respectively.5 Even when leucine concentration has been held constant, whey has been shown to be more effective at stimulating MPS.2,3
Is whey protein safe?
Whey protein is classified by the US Food and Drug Administration (FDA) as generally recognized as safe (GRAS) under 21 CFR 184.1979 and 1979a-c, and the different forms of whey have been confirmed by FDA within GRAS Notice No. GRN 000037. Though hydrolysates are not specifically listed as GRAS, the class I classification of enzymatically hydrolyzed proteins and acid hydrolyzed proteins would seem to strongly support the GRAS-recognized status for any form of whey, including hydrolysates.
Warnings on product labeling, as well as a product’s marketing may also want to communicate the following:
- 1) Persons clinically diagnosed to be lactose intolerant should avoid whey protein concentrate (WPC) that isn’t lactose-free, but should be able to consume at least moderate amounts of whey protein isolate (WPI) or a whey protein hydrolysate (WPH) derived from a WPI; and,
- 2) Though whey protein allergies are quite rare (casein is the more allergenic of the two milk proteins), β-lactoglobulin allergies can occur in some individuals. Extensively hydrolyzed (> 20-25 DH) forms of whey, however, have been shown to significantly reduce or even prevent allergic responses; which, in addition to improved growth- and immune-system supporting benefits, is why moderate-to-high degree of hydrolysis WPH is the preferred protein source in preemie and infant baby formulas.
- Qi PX et al. Effect of homogenization and pasteurization on the structure and stability of whey protein in milk. J Dairy Sci 2015;98(5):2884-97.
- Roberts M.D. et al. Hydrolyzed whey protein causes robust elevations in numerous intramuscular anabolic indices compared to a high dose of L-leucine: an in vitro approach. in ACSM Conference on Integrative Physiology in Exercise. 2014, American College of Sports Medicine: Miami Beach, FL.
- Mobley CB et al., Comparative effects of whey protein versus L-leucine on skeletal muscle protein synthesis and markers of ribosomal biogenesis following resistance exercise. Amino Acids 2016;48(3):733-50.
- Kraemer WJ et al. The effects of soy and whey protein supplementation on acute hormonal responses to resistance exercise in men. J Am Coll Nutr 2013;32(1):66-74.
- Tang, J.E., et al., Ingestion of whey hydrolysate, casein, or soy protein isolate: effects on mixed muscle protein synthesis at rest and following resistance exercise in young men. J Appl Physiol (1985), 2009. 107(3): p. 987-92.
The views, opinions and technical analyses presented here are those of the author, and are not necessarily those of UL, ULProspector.com or Knowledge.ULProspector.com. While the editors of this site make every effort to verify the accuracy of its content, we assume no responsibility for errors made by the author, editorial staff or any other contributor. All content is subject to copyright and may not be reproduced without prior authorization from Prospector.